[PATCH] D22279: [ADT] Add FlagsEnum, used to enable bitwise operations on enums without static_cast.

[Chandler Carruth via llvm-commits]

chandlerc accepted this revision.
chandlerc added a comment.
This revision is now accepted and ready to land.

Nit picks below, but LGTM. I think we should ship this. We can iterate on it further if folks want in post-commit, this already seems really nice.


================
Comment at: include/llvm/ADT/BitmaskEnum.h:19
@@ +18,3 @@
+
+/// \brief LLVM_MARK_AS_BITMASK_ENUM lets you opt in an individual enum type so
+/// you can perform bitwise operations on it without putting static_cast
----------------
We have auto-brief, so no '\brief' needed.

================
Comment at: include/llvm/ADT/BitmaskEnum.h:40
@@ +39,3 @@
+/// The parameter to LLVM_MARK_AS_BITMASK_ENUM should be the largest individual
+/// value in your enum.  All of the enum's values must be non-negative.
+#define LLVM_MARK_AS_BITMASK_ENUM(LargestValue)                                \
----------------
As mentioned in IRC, maybe put the last sentence in its own paragraph so it stands out a bit more.

================
Comment at: include/llvm/ADT/BitmaskEnum.h:67-75
@@ +66,11 @@
+
+/// Traits class to determine whether an enum has a
+/// LLVM_BITMASK_LARGEST_ENUMERATOR enumerator.
+template <typename E, typename Enable = void>
+struct is_bitmask_enum : std::false_type {};
+
+template <typename E>
+struct is_bitmask_enum<
+    E, typename std::enable_if<sizeof(E::LLVM_BITMASK_LARGEST_ENUMERATOR) >=
+                               0>::type> : std::true_type {};
+
----------------
Any particular reason to not provide the is_bitmask_enum in the llvm namespace for general use?


http://reviews.llvm.org/D22279